The drip-feed of teasers for the new BMW 8 Series continues, this time with official images of a camouflaged prototype and new details about one of its powertrains.

As BMW enters the "final stage of the series production process", we're given a quick preview of the M850i xDrive – which is claimed to embody "the performance characteristics of the new luxury sports car in a particularly intensive manner".

Under the bonnet of the new M Performance model is a "completely redeveloped" V8 petrol engine – likely to be a 4.4-litre twin-turbocharged unit. It claims outputs of 390kW and 750Nm, the latter available from just 1800rpm.

That represents increases of 50kW and 100Nm over the engine currently used in 50i BMW models, with drive sent through an eight-speed Steptronic sports automatic transmission.

"The new V8 engine offers exactly the right balance between performance and emotion, which is what also sets the new BMW 8 Series Coupe apart," said Christian Billig, head of drive system integration.

"Above all, the eight-cylinder harmonises perfectly with the further developed Steptronic transmission during dynamic acceleration."

"At the same time, the sound development of the sports exhaust system authentically reflects the car’s power delivery. And thanks to BMW xDrive and active rear axle locking, the engine always transfers power precisely to where it can be best converted into driving dynamics," he added.

The M850i's performance-oriented xDrive all-wheel drive system is rear-biased, while other features include an active rear differential lock, adaptive M suspension with active roll stabilisation, and Integral Active Steering.

Further details about the new 8 Series range will be revealed at the vehicle's launch – likely later this year – though an official date is yet to be confirmed by the Bavarian marque.

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